The immune system and the nervous system maintain extensive communication, including 'hardwiring' of sympathetic and parasympathetic nerves to lymphoid organs. Neurotransmitters such as acetylcholine, norepinephrine, vasoactive intestinal peptide, substance P and histamine modulate immune activity.
It would be A. That’s the point of a flu shot. U inject the virus to make your body know it’s bad and when It comes along again to fight it hard.
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its answer is B hope ur help and mark me as brainlist
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The larger the amplitude of the waves, the louder the sound. The faster the vibrations, the higher the pitch (frequency) of the sound.
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